Hops are universally used in the production of malt beverages such as beer or ales, because they impart important properties to these beverages. These include preservative, or anti-microbial properties, particularly against gram negative organisms; bitterness, imparted by a set of organic compounds called “humulones,” which are isomerized by the brewing process to a related set of compounds called “isohumulones;” aroma, a uniquely floral bouquet, characterized as “hop bouquet;” and foam enhancement, or “lacing,” due to surface properties of some components of hops. In the U.S. the use of hops is mandatory by the United States Bureau of Alcohol and Firearms, in the amount of 7.5 lbs. per 100 bbls. of brewed beer. In all other countries, the use of hops is mandated by custom and the special properties of hops.
Beers and ales are made by an infusion of barley malt and other grains into warm water. Conventional mashing involves mixing together of malt and cereal adjuncts in warm water, followed by a series of heating and resting cycles. Following mashing, the soluble materials are extracted in a lauter tub, leaving behind the spent grain. A clear liquid (wort) obtained by the extraction may then be transferred to a brew kettle and boiled for a period of time which inactivates the malt enzymes, and extracts the bitterness principles of hops. Wort compositions vary depending on raw materials and mash cycles employed.
A typical wort used in brewing may be composed of the mixed extract of a barley malt mash and a cereal adjuncts mash, typically of corn grits or rice. Such mixed extract may be obtained by treating a dried barley malt with warm water, at about 50° C., in one vessel, the so-called “mash tub” and boiling the cereal adjuncts, (e.g. corn grits or rice) in another vessel, the so-called “cooker,” and then adding the boiling contents of the cooker to the warm malt suspension in the mash tub. This serves to raise the temp. of the mash tub contents to about 57°-67° C. During the rise from 50° C., to about 67° C., and starting at around 63° C., the enzymes in the malt and in particular beta-amylase which is most active between 60° and 70° C., partially degrade the starches in both the malt itself and in the corn grits or rice to form simple fermentation sugars, primarily glucose, fructose and maltose. These simple sugars are fairly sweet tasting, and also are fermentable by Brewers' years to alcohol and carbon dioxide.
The combination mash is then filtered in a lauter tub, mash filter or other means and the resulting wort boiled with hops to extract the bitter components and other components, filtered, cooled and fermented with yeast, and carbonated to produce a beer or ale.